COLUMBIA, S.C.--Mitt Romney's election night party never felt like a victory rally. As supporters filed in shortly before local polls closed, the mood was somber. But soon, dozens of college kids—many of them bused in from other states in recent days—filled the bleachers behind Romney's podium and began chanting the key talking point Romney aides are pushing after his loss to Newt Gingrich here tonight.

"Florida, here we come!" they yelled, as a Romney volunteer, acting the role of a spirit leader, waved her arms wildly to pump up the group. "FLORIDAAAAAH!!"

Arriving on stage a few moments later, Romney barely mentioned Gingrich's name. Yet in tougher remarks than those he's delivered on the trail in recent days, it was clear whom he was referring to in a series of attacks.

"Our party cannot be led to victory by someone who also has never run a business, and never run a state," Romney declared. "We cannot defeat [President Obama] with a candidate who has joined in that very assault on free enterprise."

"Those who pick up the weapons of the left today will find them used against them tomorrow," Romney continued, adding that Republicans who embrace such attacks aren't fit to be the nominee.

That's likely to be Romney's message in Florida next week, as he looks to rebound in a state where his campaign has already invested millions of dollars in staff and other political infrastructure.

Speaking to reporters afterwards, Stuart Stevens, Romney's chief political strategist, echoed the line the campaign has played up recently, as it became clear Gingrich was rising in the polls here.

"No one has run the table," Stevens said, adding that the campaign is focused on the the "long haul" of the primary fight.

On stage, Romney said the political setbacks are making his campaign "stronger."